Latin
meaning
example or comment
ad hoc
formed or done for a particular purpose only
An ad hoc committee was set up to oversee the matter.
ad nauseam
repeating or continuing to the point of boredom
The apparent risks of secondary smoking have been debated ad nauseam.
bona fide
genuine; real
Only bona fide members of the club may use the clubhouse.
caveat emptor
let the buyer beware
The principle that the buyer is responsible for checking the quality and suitability of goods before a purchase is made.
circa; c.
around; approximately
The house was built circa 1870.
compos mentis
in control of the mind (often used ironically)
Please call me back later when I'm compos mentis.
de facto
in fact; in reality
Although the Emperor was the head of state, the de facto ruler of Japan was the Shogun.
ergo
therefore
cogito ergo sum
erratum
error; mistake
Lists of errors from a previous publication are often marked "errata" (the plural, meaning errors).
et cetera; etc
and the rest; and so on; and more
We urgently need to buy medical equipment, drugs et cetera.
ex gratia
from kindness or grace (without recognizing any liability or legal obligation)
They received an undisclosed ex gratia payment.
ex libris
from the books; from the library
In the front of a book: Ex Libris John Brown
habeas corpus
a court order instructing that a person under arrest be brought before a judge
The right of habeas corpus has long been regarded as an important safeguard of individual liberty.
in loco parentis
in the place of a parent
Teachers sometimes have to act in loco parentis.
in situ
in its original place
The paintings have been taken to the museum but the statues have been left in situ.
in vitro
(in biology) taking place outside a living organism (for example in a test tube)
in vitro fertilization
inter alia
among other things
The report covers, inter alia, computers, telecommunications and air travel.
per
for each
This petrol station charges $5.00 per gallon.
per annum; p.a.
for each year
The population is increasing by about 2% per annum.
per capita
for each person
The country's annual income is $5000 per capita.
per se
in itself/themselves; intrinsically
These facts per se are not important.
post-mortem
examination of a body after death; autopsy
The post-mortem revealed that she had been murdered.
pro rata
proportional; proportionally
The car rental charge is $50 per day and then pro rata for part of a day.
quid pro quo
favour or advantage given or expected in return for something
Similar to "tit for tat", "give and take" and "You scratch my back and I'll scratch yours."
re
about; concerning; regarding
Re: Unpaid Invoice

I spoke to the manager re your salary increase.

sine qua non
essential condition; thing that is absolutely necessary; "without which not"
Words are a sine qua non of spoken language.
status quo
existing state of affairs
Monarchies naturally wish to maintain the status quo.
terra firma
dry land; the ground as opposed to the air or sea
Shackleton and his men set foot on terra firma after three weeks at sea.
verbatim
in exactly the same words
I had to memorize the text verbatim.
versus; vs.; v.
against
What are the benefits of organic versus inorganic foods?

In the case of Bush versus Gore, the judges decided...

vice versa
the other way round
My telephone serves me, and not vice versa.
persona non grata
unacceptable or unwelcome person
From now on, you may consider yourself persona non grata in this house.